Read-write memory read instruction(03)
Instruction example
Format of command (03) from master
Byte# | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
Node ID | Slave Address | Function Code | Address of first reading register | Address of first reading register | Quantity of registers to be read | Quantity of registers to be read | CRC | CRC |
Example 01~FF | 01 | 03 | 00 | 00 | 00 | 03 | 05 | CB |
Description of master command
The example will read A01 pipe diameter options and A02 Scale Factor.
slave address: 01(address of this flowmeter)
function code: 03(read instruction)
Address of first reading register: 0000(Address of first register to read)
Quantity of registers to be read: 0003 (need to read 2 registers from 0000)
CRC: 05 CB (Calculating error correcting code according to CRC algorithm)
Format of flowmeter response(03)
Byte# | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
Node ID | Slave Address | Function Code | Amount of response Byte | Data Byte #1 | Data Byte #2 | Data Byte #3 | Data Byte #4 | Data Byte #5 | Data Byte #6 | CRC | CRC |
Example 01~FF | 01 | 03 | 06 | 00 | 00 | 3F | 80 | 00 | 00 | 2C | 89 |
Description of flowmeter response example
slave address: 01(address of this flowmeter)
function code: 03(read instruction)
Amount of response Byte: 06 (3 register=6byte)
Data Byte:
00 00(Current pipe diameter is 1inch PVC)
3F 80 00 00(Current Scale Factor is 1.0)
CRC: 2C 89 (Calculating error correcting code according to CRC algorithm)
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